#ifndef LIST_H
#define LIST_H

#include <stdlib.h>

/*
 *  Define a structure for linked list elements. 
 */

typedef struct ListElmt_ {
  void               *data;
  struct ListElmt_   *next;
} ListElmt;

/*
 *  Define a structure for linked lists.
 */
typedef struct List_ {
  int                size;
  int                (*match)(const void *key1, const void *key2);
  void               (*destroy)(void *data);
  ListElmt           *head;
  ListElmt           *tail;
} List;

/*
 * Public Interface
 */
void list_init(List *list, void (*destroy)(void *data));
void list_destroy(List *list);
int list_ins_next(List *list, ListElmt *element, const void *data);
int list_rem_next(List *list, ListElmt *element, void **data);
#define list_size(list) ((list)->size)
#define list_head(list) ((list)->head)
#define list_tail(list) ((list)->tail)
#define list_is_head(list, element) ((element) == (list)->head ? 1 : 0)
#define list_is_tail(element) ((element)->next == NULL ? 1 : 0)
#define list_data(element) ((element)->data)
#define list_next(element) ((element)->next)

#endif /* LIST_H */
